Rubber Balloons for Culvert Making (600mm, 900mm, 1200mm)

Brief introduction to mandrel of pneumatic rubber
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Mandrel of pneumatic rubber also refers to air case, capsule, etc. It is a kind of inflatable (air inflation) and shrinkable (air deflation) tape product. It can be made in various shapes according to user demands. When using it, it should be pulled into reinforcement cage with compressed air filled and concrete pouring should be carried out, and then compressed air can be released and mandrel of pneumatic rubber can be pulled out after initial set of concrete. In this way, beam slab will be of hollow form as needed.
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Construction practice proves that not only materials can be saved, but also many shapes can be made by using prefabricated capsule parts. It can be made in round shape, oval, rectangle, octagon, trapezoid and variable cross-section form, which greatly reduces labour intensity of workers, increases efficiency and saves production cost. Therefore, it is widely used for highway, railway, water conservancy, dock and wharf.
Performance Features
1,
Scientific and reasonable design.
Both rubber inflatable andrel and prefabricated or cast-in-place finished components can meet design requirements with features of easy operation and saving labour, time and materials. 2,
Excellent ageing-resistant performance and long service life. .
The product is made of synthetic rubber, natural rubber and vulcanized reinforced layer, which provides the product with excellent anti-expansion strength, elasticity and flexibility, thus it is capable of meeting the application requirements of all kinds of working conditions. 3,
Wide applicative temperature range
The material has no change under the temperature of -10ºC~+90ºC. 4,
It provides strong conditions for light-weight trend of building site construction. .
For prestressed hollow concrete components, its weight is 30% lighter than non-prestressed solid components due to the application of rubber mandrel. Therefore, reducing the weight of upper structure of building can shorten pile foundation and increase span, which makes the on-site construction easy and safe. 5,
Simple, safe and hygeian construction process.
only a few simple tools rather than special processes are required when using rubber mandrel. Concrete can be poured only by putting mandrel into reinforcement cage when inflation pressure reaches working pressure. During initial set of concrete, mandrel can be deflated and taken out, so as to mould finished components without environmental pollution. Schematic Diagram of Service Pressure
Circular diameter (mm)
Service air pressure (Mpa)
Whole oval (mm)(
Service air pressure (Mpa)
Circular diameter (mm)
Service air pressure (Mpa)
Whole oval (mm)
Service air pressure (Mpa)
Octangle air case
Service air pressure (Mpa)800.1780x3600.0184000.038600x3000.019800x710x210.0141200.09670x5500.0185000.029290x2400.020800x560x170.0161500.078540x3600.0206250.026450x3300.021800x460x140.0172000.068440x3600.0207600.025510x3300.021550x710x210.0152500.048550x3500.0188000.024700x530x5900.020550x560x170.0163000.043800x3400.0139000.023940x5800.016550x460x140.017
Application of MandrelMoulding1
Mandrel surface shall be uniformly coated with separant before putting into cage. Separant ratio: water : washing powder : talcum powder=10:1:2.
2. .
Pull mandrel into reinforcement cage with concrete floor laid. Air inflation
Open valve and inflate to specified pressure. Please be noted that valve joint shall be bound by teflon tape. Fixation.
Mandrel may float during construction, thus it shall be provided with locating bar and pressing block shall be applied on it. Space between locating bars is generally 30-80mm according to mandrel specifications. Concrete pouring
1.
Process after pouring concrete is basically in conformity with that of solid components.
2.
Simultaneously vibrating by using high-frequency plug-in vibrating rod from both sides can avoid mandrel movement. Model removal
After initial set of concrete, vent valve shall be opened to vent air and take out mandrel (basis conditions for air venting and demoulding time and mixing ratio of concrete shall be determined by Constructor).